Method for producing a nitride semiconductor component, and nitride semiconductor component

Abstract

The invention relates to a method for producing a nitride semiconductor component ( 10 ), comprising the following steps: epitaxially growing a nitride semiconductor layer sequence ( 2 ) on a growth substrate ( 1 ), wherein recesses ( 7 ) are formed on a boundary surface ( 5 A) of a semiconductor layer ( 5 ) of the semiconductor layer sequence ( 2 ), growing a p-doped contact layer ( 8 ) over the semiconductor layer ( 5 ), wherein the p-doped contact layer ( 8 ) at least partially fills the recesses, and wherein the p-doped contact layer ( 8 ) has a lower dopant concentration in first regions ( 81 ) arranged at least partially in the recesses ( 7 ) than in second regions ( 82 ) arranged outside of the recesses ( 7 ), and applying a connection layer ( 9 ), which has a metal, a metal alloy, or a transparent conductive oxide, to the p-doped contact layer ( 8 ). The invention further relates to a nitride semiconductor component ( 10 ) that can be produced by means of the method.

1 . Method for producing a nitride semiconductor component, comprising the following steps:
 epitaxially growing a nitride semiconductor layer sequence on a growth substrate, wherein recesses are formed at a boundary surface of a semiconductor layer of the semiconductor layer sequence,   growing a p-doped contact layer over the semiconductor layer, wherein the p-doped contact layer at least partially fills the recesses, and wherein the p-doped contact layer has a lower dopant concentration in first regions arranged at least partially in the recesses than in second regions arranged outside of the recesses, and   applying a connection layer, which comprises a metal, a metal alloy, or a transparent conductive oxide, to the p-doped contact layer.   
     
     
         2 . Method according to  claim 1 , wherein the dopant concentration in the p-doped contact layer varies in the lateral direction at a boundary surface to the connection layer. 
     
     
         3 . Method according to  claim 1 , wherein growing the p-doped contact layer is interrupted before a dopant concentration is obtained at a growth surface that is constant in the lateral direction. 
     
     
         4 . Method according to  claim 1 , wherein the p-doped contact layer has a thickness a, and the recesses have an average lateral extent b, and wherein a≤2*b. 
     
     
         5 . Method according to  claim 1 , wherein part of the p-doped contact layer is removed at least partially after being grown. 
     
     
         6 . Method according to  claim 1 , wherein, before growing the p-doped contact layer, an etching process is performed to produce and/or enlarge the recesses at the boundary surface of the semiconductor layer. 
     
     
         7 . Method according to  claim 1 , wherein at least part of the recesses are at least 10 nm wide. 
     
     
         8 . Method according to  claim 1 , wherein at least part of the recesses are at least 10 nm deep. 
     
     
         9 . Method according to  claim 1 , wherein the dopant concentration in the second regions is at least 5*10 19  cm −3 . 
     
     
         10 . Method according to  claim 1 , wherein the dopant concentration in the second regions is partially at least 1.5 times as high as in the first regions. 
     
     
         11 . Method according to  claim 1 , wherein the p-doped contact layer includes a first partial layer containing the first regions and the second regions, and a second partial layer, which second partial layer has a higher dopant concentration than the first regions and the second regions. 
     
     
         12 . Method according to  claim 1 , wherein, before growing the p-doped contact layer, an additional semiconductor layer is grown on the semiconductor layer, and wherein the additional semiconductor layer has a lower dopant concentration than the second regions of the p-doped contact layer. 
     
     
         13 . Method according to  claim 12 , wherein the additional semiconductor layer has a thickness d and the recesses have an average depth e, and wherein d>0.1*e. 
     
     
         14 . Nitride semiconductor component, comprising
 a nitride semiconductor layer sequence, with   recesses being formed at a boundary surface of a semiconductor layer of the semiconductor layer sequence,   a p-doped contact layer which at least partially fills the recesses, wherein the p-doped contact layer has a lower dopant concentration in first regions which are at least partially arranged in the recesses than in second regions arranged outside of the recesses, and   a connection layer made of a metal, a metal alloy or a transparent conductive oxide which follows the p-doped contact layer.   
     
     
         15 . Nitride semiconductor component according to  claim 14 , wherein the dopant concentration in the p-doped contact layer varies in the lateral direction at a boundary surface to the connection layer. 
     
     
         16 . Nitride semiconductor component according to  claim 14 , wherein the dopant concentration in the second regions is at least partially 1.5 times as high as in the first regions. 
     
     
         17 . Nitride semiconductor component according to  claim 14 , wherein the nitride semiconductor component is an optoelectronic component, wherein the semiconductor layer sequence includes an n-type semiconductor region, a p-type semiconductor region and an active layer arranged between the n-type semiconductor region and the p-type semiconductor region, and wherein the p-type semiconductor region comprises at least the semiconductor layer and the p-doped contact layer. 
     
     
         18 . Method for producing a nitride semiconductor component, comprising the following steps:
 epitaxially growing a nitride semiconductor layer sequence on a growth substrate, wherein recesses are formed at a boundary surface of a semiconductor layer of the semiconductor layer sequence,   growing a p-doped contact layer over the semiconductor layer, wherein the p-doped contact layer at least partially fills the recesses, and wherein the p-doped contact layer has a lower dopant concentration in first regions arranged at least partially in the recesses than in second regions arranged outside of the recesses, and   applying a connection layer, which comprises a metal, a metal alloy, or a transparent conductive oxide, to the p-doped contact layer,   wherein the dopant concentration in the p-doped contact layer varies in the lateral direction at a boundary surface to the connection layer.